Programming Assignment Stack Class

Programming Assignment
Your code must be able to compile for Java 8. Because the assign-
ment is graded with TAs’ unit test suite, any code that cannot be compiled
with Java8 will receive a grade of 0 for correctness part.
You must include a testing class in which you use JUnit tests to test each
of your methods. Your tests must cover all lines of code in your methods, and
they should account for edge cases in situations involving loops or recursion.
Please refer to this tutorial if you are unsure how to set up or write JUnit
tests: https://www.tutorialspoint.com/junit/junit quick guide.htm.
You must include comments alongside your code. You should include a
comment before each flow statement (if, for, while, etc.) and wherever you
have complex blocks of code which have a purpose that is not immediately
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discernible. Be sure to also use appropriate and meaningful variable names
throughout your code.
You may not import any libraries from the Java API in your implemen-
tation, though you may use them in your testing class. You may use Java
classes that do not require importation such as String or Math. Be sure to fol-
low good encapsulation practices (no public classes, methods, or fields other
than the ones listed below), and refer to the rubric for grading procedures.
For the first part of the programming assignment, you will be implement-
ing a Stack class. The Stack should not have any limit in capacity, so you
should determine when it should resize to have more elements inside. The
Stack should have the following fundamental functions:
public class Stack<T extends Comparable<? super T>>
• boolean push(T value) - given a value as input, pushes it into
the stack. The function returns true if it succeed in inserting, otherwise,
false.
• T pop() - tries to delete the element at the front of the stack. The
function returns the value of the front element if it succeeds, otherwise,
returns null.
• T peek() - returns but not deletes the value of the front element in
the stack if there is any; otherwise, it should return null.
For the second part of the programming assignment, you will be imple-
menting a StringManipulation class that can perform the followings
operations:
public class StringManipulation
• static String toPostfix(String infix) - takes in a string
of infix expression and returns the postfix expression for that string.
The input string will be a legal infix expression and has the follow-
ings characters: numbers, operations (+,-,*,/), left parenthesis ”(”,
and right parenthesis ”)”.
• static int result(String postfix) - takes in a string of post-
fix expression and returns the final value of that expression. The input
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string will be a legal postfix expression and has the followings char-
acters: spaces, numbers, and operations (+,-,*,/). There will be one
space between each pair of numbers, or pair of a number and an opera-
tion. Please note that operation ”/” is an integer division, i.e. cutting
of anything to the right of the decimal points. The numbers in the
postfix expression can have multiple digits but will be in the range of
int primitive type.
For example: a valid postfix expression is ”3 20 + 6 -”.
• static String smallestNumber(String number, int n) -
takes in a string containing only digits from 0 to 9 representing a num-
ber, and an integer n such that n is less than or equal to the length of
the string. The functions should return the smallest number obtained
by deleting n digits from the input string.
The result string should not have any leading zeroes, and deleting lead-
ing zeros should not count toward n digits. For example, number =
”70004” and n = 1, so the result should be ”4” by deleting digit ”7”.
• static String unbelievableString(String s)- takes in a
string containing only lowercase and uppercase English letter, and re-
turns the unbelievable string obtained by deleting some characters
from the input string such that the following condition hold: The un-
believable string is a string without any two adjacent characters
s[i] and s[i + 1] such that:
– 0 ≤ i ≤ s.length − 2
– s[i] is an uppercase letter and s[i + 1] is the same letter but in
lowercase or vice-versa.
For example, we have a string ”abDDdddE”. Now there are ”Dd” in
”abDDdddE” that doesn’t satisfy the condition, so we will delete these
two characters to have the string ”abDddE”.
Next, ”abDdde” still has ”Dd”, so we will delete these too, and have
the final result string ””abdE” satisfying the condition.